The term 'CERTAIN DOMINICAN' can be solved by the 3-letter word 'NUN'. A NUN is a woman who has taken religious vows and dedicated her life to serving God and the Church. Nuns are often associated with the Catholic Church, and many of them belong to religious orders such as the Dominican Order. The Dominican Order is a Catholic religious order founded in 1216 by Saint Dominic de Guzman. The members of this order are known as the Friars Preachers, and they are committed to preaching the Gospel and living a life of poverty and service.